LAS VEGAS >> Middleweight fighter Julio Cesar Chavez Jr. could be stripped of his $3
million purse, depending on the explanation he offers to Nevada boxing
regulators about a positive test for marijuana after his first
professional loss last weekend in Las Vegas, officials said today.

"Julio
Cesar Chavez Jr. will have the opportunity to explain the situation to
the Nevada State Athletic Commission," Samuels said in a statement he
read to a reporter. Samuels declined further comment.

Commission
executive Keith Kizer wouldn't immediately provide the name, but said
only one of 32 fighters who took part in bouts at two Las Vegas venues
last Saturday tested positive for a banned substance, marijuana.

Kizer
said the commission was awaiting results of pre-fight tests for banned
steroids, diuretics and masking agents before releasing all pre-fight
and post-fight test results for all 32 fighters.

The commission can ban a fighter for one year and penalize him for up to 100 percent of his purse for a failed test, Kizer said.

Chavez was guaranteed $3 million for the WBC title fight against Sergio Martinez.

Martinez
dominated the first 11 rounds in the 160-pound fight at the Thomas
& Mack arena, but had to withstand a frenzied 12th round effort by
Chavez to win a unanimous decision. Martinez ran his record to 50-2-2.

Chavez fell to 46-1-1 with 32 knockouts.

He
was suspended before, for seven months, and his 10-round unanimous
decision win in November 2009 over Troy Rowlands was changed to a
no-contest after he tested positive for a banned diuretic.

Chavez
was arrested on drunken driving charges Jan. 22 in Los Angeles, and
struggled to make weight for a championship bout in February against
Marco Antonio Rubio in San Antonio, Texas.